RestTemplate 遇到泛型参数时，用exchange方法

#发送参数：

EpbParam param = new EpbParam();
param.setData(CouponOrder);

#参数 httpEntity组装
 HttpHeaders headers = new HttpHeaders();
 headers.setContentType(MediaType.APPLICATION_JSON);
 HttpEntity> entity = new HttpEntity>(param, headers);






#返回值 ParameterizedTypeReference 

ParameterizedTypeReference parameterizedTypeReference = new ParameterizedTypeReference>() {};
ResponseEntity> result = restTemplate.exchange(url, HttpMethod.POST, entity, parameterizedTypeReference);result.getBody();